Stabilized polythionates as



Reissued Sept. 8, 1953 STABILIZED POLYTHIONATES AS MEDICINAL COSMETICS Torben Emil Neesby, New Brunswick, N. .L, assignor, by mesne assignments, to Carroll Dunham Smith Pharmacal 00., New Brunswick, N. J., a corporation of New Jersey N Drawing. Original No. 2,551,627, dated May 8,

1951, Serial No. 620,637, October 5, 1945. Application for reissue April 29, 1952, Serial No. 285,089. In Norway January 2, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires January 2, 1961 Matter enclosed in heavy brackets II appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

6 Claims.

The invention concerns sulphur compounds in the form of polythionates and the application thereof for industrial, cosmetic, medicinal or other purposes, and aims at the production of polythionates and/or polythionic acids which are stable for a long time in solution. The invention embraces also the production of higher polythionates, namely those containing more than 6 atoms of sulphur per molecule of polythionate, it being of essential importance that such polythionates shall during or after production be subjected to a stabilisation process whereby the spontaneously proceeding decomposition is stopped. It is known from the literature that solutions of polythionates in the course of some few weeks undergo various changes, the polythionate molecule being broken down, with formation of higher or lower compounds and with the final result that the quantity of polythionate present is converted to sulphate, sulphite and crystalline sulphur.

This instability, which-howeverdoes not prevent the production of pure polythionate salts, seems mainly to lie in the polythionate molecule itself, when this is in process of dissolution, although the instability may also be due to the presence in the solution of other ions, such as hydroxyl ions.

It is known from the literature that certain polythionates have a rather strong bactericidal effect. It has now been found possible to demonstrate that polythionates and polythionic acids both in organic and inorganic solutions can with great advantage be employed as cosmetics, for skin treatment and as prophylactic and curative agents in various diseases. In connection with the present invention polythionates and polythionic acids have therefore been subjected to careful investigation in order to solve the problem of producing solutions of these substances which will be stable for a considerable time, which is imperatively necessary if the application of such solutions is to acquire practical importance. A solution of this problem has now been reached, since by the procedure according to the invention it has been found possible to counteract the spontaneous or gradually arising decomposition of the molecules, in other words, to find some negative catalyst which is capable of preventing or checking the decomposition for the longest possible time.

It is found that the decomposition of the polythionates is dependent not only on the foreign substances that may be added, but also in some degree upon the concentration of the polythionate ions. The decomposition is likewise dependent on the temperature, being accelerated during rising temperatures.

It is obvious that this instability render it difficult to produce pure solutions of polythionic acids, 1. e., solutions containing only one kind of polythionate, since the molecules by degrees become divided up so as to form polythionates with molecules of greater or smaller size.

According to the invention stable aqueous solutions of polythionates or polythionic acids are obtained by adding to the freshly prepared solutions substances which are capable of regulating the redox potential, such as oxygen-emitting or electron-absorbing compounds, desirably a sm ll amount of a cupric or ferric compound which is suflicientl'y soluble in the aqueous solution to "which the compound is added to form cations is thus added.

Although from the composition of the polythionates they might be supposed to be powerful reductives, yet they do not react with iodine or potassium iodide solutions until after the lapse of some days, whereas with respect to stronger oxidising agents, such as permanganate and chromate, as well as large quantities of nitrite, they act as pronounced reductives. It is therefore probable that they have no definite redox potential, but that this is dependent on the catalysts present.

If care is now taken, by addition of oxygenemitting agents to ensure that rH has a sumciently high buffering value, by means of cupric or ferric ions or other ions or substances with similar properties, it will be observed that the decomposition of the polythionates is very effectively prevented.

Special advantages are attained by adding to the solution at a suitable moment acids or bases in such quantity that the final product has a pH which has been found by experience to be the most desirable. This addition, for instance of bases, may include both inorganic and organic compounds and may easily be made to coincide with the regulation of the rH. [For example, one] One may add appropriate quantities of cupric or ferric compounds, such as hydroxides :nomenon only in slight degree.

or carbonates, to stabilize the polythionates or polythionic acids. [whereby cupric or ferric polythionates in more or less pure solution can be obtained at will] Furthermore, it has been found advantageous for certain purposes to prepare a solution of polythionic acids or polythionates in organic solvents, so that the finished product will contain more or less water. [or even none at all] Thus, for example, an alcoholic solution of [cupric] pentathionates, made in accordance with invention, will be stabile, since its pH and its rH are fixed and a stabiliser is present. The solutions prepared according to the invention are [may be given any desiredposition between] aqueous solutions of polythionate or polythionic acid with fixed pH and HE as-well as with stabilisers. [and pure organic solutions of metallic polythionates] The higher polythionates are, as was to be expected, still more [stable] unstable than the generally known forms, and it is therefore essential for their employment for technical purposes that their [condensation can] decomposition be stopped, i. e., that they be stabilized. The employment of the higher polythionates in medicine offers special advantages, as they have a physiological sulphur effect which is still stronger than that of the lower ,polythionates and it is therefore of great service in the production of skin preparations from polythionates to let the ingredients include some of the higher polythionates.

Polythionates and especially the higher forms can with particular advantage be employed in cosmetics and medicine instead of colloidal sulphur.

When solutions of colloidal sulphur are used for superficial application, as is usual in treat- .ment of skin and hair, the object or surface treated will acquire a yellow or white appearance.

In many cases it will be extremely undesirable to let the object treated acquire such a colour, especially in treatment of scalp and hair, which thereby comes to have a grayish or whitish appearance. The treatment in such cases must be combined with subsequent washing in order to eliminate the further effects of the sulphur employed.

In the application of .the method there is taken, for example, an ordinary crude sulphur sol, for instance, a [Wackenroder] Wachenroder solution, which probably contains all the possibly existing polythionates and higher complexes, and the fractions containing the ordinary polythiomates and the aforesaid higher polythionates, or compounds of such empirical composition, are separated on by means of fractional precipitation, concentration or the like.

It has been found that with thus prepared solutions of the compounds in question, hair and skin may be treated without becoming stained, as is the case when using colloidal sulphur, provided that the acidity of the solution is adjusted to a pH of less than 5, preferably less than 3', by aid of strong acids, such as sulphuric acid, hydrochloric acid, but especially polythionic acid.

That the solutions produced do not contain material quantities of colloidal sulphur is clear from the fact that they show the Tyndall phe- In ordinary light the solutions areof yellow-green colour and vtare quite clear.

Below are sivensome examples of modes. of

4 execution which will serve to illustrate the application of the invention:

1. An [alkaline] alkali metal salt prepared in known manner from tetrathionic acid is dissolved in distilled water to a strength of about 2pm cent. The pH is adjusted to 1.5 with pure hydrochloric acid. After addition of 1 gm. of thyrosine, the solution is placed in a [thermostat] heated chamber thermostatically maintained at 50 C. and in the course of 14 days a decrease in the 'tetrathionate concentration of 3 millimols per litre is observed, while a sample without thyrosine showed a decrease of about "5 millimolsper litre in the same period.

2. As in Example 1, with further addition of 2 cubic cm. of a normal copper sulphate solution per litre. In .the course of one week in the [thermostat] heated chamber at 50 C. a decrease of 1.5 millimol of tetrathionate per litre was observed.

The stabilized solutions of tetraand pentathionates have a powerful sulphur action, which can not only be utilized for cutaneous application, but also renders the solutions specially suitable for use when it is a question of injections ,for widely difierent purposes in the field of medical science. The polythionates can also be emvployedfor technical purposes and for the spraying of plants.

I claim:

I. .A composition of matter comprising a cosmetic base, a compound having the formula 12281106 in which R is a cation of the group consisting of H Li Na+ and K+ and n is an integer 4 or 5,, and, in intimate physical association with the compound, a negative catalyst of the group consisting of .cupricand ferric ions added as a salt .inanamoun't which is in very small proportion withrespect to the compound of the thionic radical which suppresses the decomposition of the thionicradical S1106 and the resulting liberation of elemental sulphur and sulphur dioxide for relatively long periods when the composition is .at room temperature and in contact with water, whereby the solution remains clear.

.2. A composition of matter comprising a cosmetic base, a compound havin the formula RzSnOs in which R is from the group consisting of hydrogen and an alkali metal and n is an integer from 4 to .6 inclusive, and in intimate physical association with said compound, a metal compound from the group consisting of cupric and ferric compounds, which when dissolved in ancqueous medium ioniee and form cations, said metal compound being present in very small profrom the group consisting of cupric and. ferric salts, which when dissolved in an aqueous medium ionize and form cations, said salt being present in every small proportions with respect to said compound and suppressing the decomposition of said compound and the resulting libera- "tion of elemental :sulphur and sulphur dioxide for relatively long periods when the compound is at room temperature and in contact with water, whereby the solution remains clear.

4. A stabilized aqueous solution of a compound having the formula R2Sn06 in which R is from the group consisting of hydrogen and an alkali metal and n is an integer from 4 to 6 inclusive, said solution containing a small proportion of a metallic compound from a group consisting of cupric and ferric compounds sufiiciently soluble in said solution to ionize and form cations.

5. A stabilized aqueous solution of a compound having the formula RgSnOi in which R is from the group consisting of hydrogen and an alkali metal and n is an integer from 4 to 6 inclusive, said solution containing a small proportion of a salt from a group consisting of cupric and ferric salts sufiiciently soluble in said solution to ionize and form cations.

6. A stabilized aqueous solution of an alkali metal salt having the formula MzSnOs in which M is an alkali metal and n is an integer from 4 to 6 inclusive, said solution containing a small proportion of a metal salt from the group consisting of cupric and ferric salts.

TORBEN EMIL NEESBY.

Name Date Jacobson Feb. 10, 1931 Number Number Name Date 1,832,325 Rosenstein Nov. 17, 1931 1,843,224 Hansen Feb. 2, 1932 1,917,351 Young July 11, 1933 5 1,944,978 Hansen Jan. 30, 1934 1,949,797 Kaufmann Mar. 6, 1934 1,979,934 Hansen Nov. 6, 1934 1,980,236 Torigian Nov. 13, 1934 2,149,249 Nitsche Feb. 28, 1939 0 2,201,124 Ehman et a1. May 14, 1940 FOREIGN PATENTS Number Country Date 344,841 Great Britain Sept. 9, 1929 15 379,436 Germany Feb. 11, 1922 632,927 Great Britain Dec. 5, 1949 OTHER REFERENCES Longmans, Green and Co., New York, pages 477 Deines et al.: Chemical Abstracts, vol. 27, page 5018, 1933.

Stamm et al.: Chemical Abstracts, vol. 35, page 3185, 1941. 

